.RENSENWARE File Extension

In 2017, developer Kangjun Heo created rensenWare. Like typical ransomware, rensenWare maliciously encrypts and renames a user's files. Unlike typical ransomware, rensenWare does not ask users to pay a ransom to decrypt their files. Instead, it requires users to achieve a score of 200 million points in the Lunatic difficulty of Touhou Seirensen ~ Undefined Fantastic Object, a scrolling shooter video game. (RensenWare does not include Touhou Seirensen ~ Undefined Fantastic Object, so users had to acquire and install it themselves.)

After accidentally infecting his own computer with rensenWare, Heo created a tool that allows players to automatically set their Touhou Seirensen ~ Undefined Fantastic Object score to 200 million, to terminate the ransomware and restore infected files. Later, Heo iterated on this tool and created a version that does not require users to install or play Touhou Seirensen ~ Undefined Fantastic Object to decrypt their files.

To open a .rensenware file, you need compatible software that supports this file format.